Browse Prior Art Database

Method for a substrate soldermask plateau for improved die-attach coverage

IP.com Disclosure Number: IPCOM000012201D
Publication Date: 2003-Apr-16
Document File: 3 page(s) / 80K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for a substrate soldermask plateau for improved die-attach coverage. Benefits include improved performance.

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 55% of the total text.

Method for a substrate soldermask plateau for improved die-attach coverage

Disclosed is a method for a substrate soldermask plateau for improved die-attach coverage. Benefits include improved performance.

Background

              Die-attachment material bleeds out on flexible (flex) substrates that do not have topside soldermask. When die-attach material is placed on a flex substrate without soldermask and silicon is placed on the substrate, the die-attach material tends to bleed out along traces underneath the silicon. The die-attach material can bleed out between parallel traces and infringe on bond fingers.

              This problem is conventionally addressed with the careful control of the die-attach volume and the pattern placement on the substrate. However, the problem still occurs.

General description

      The disclosed method is a substrate soldermask plateau for improved die-attach coverage.

Soldermask is selectively applied in the die-attach area (only) at the same height as traces to create a smooth plateau for silicon die-attach during assembly.

 

              The key element of the method is a selective application of soldermask in the die-attach area of a substrate to create a flat surface for optimal die-attach epoxy spreading during assembly.

              The disclosed method does not compromise the z-height of the substrate or finished package. The method is compatible with nonconductive die-attach materials, such as paste or film.

Advantages

              The disclosed method provides advantages, including:

•             Improved performance due to improved die-attach coverage because of selective placement of soldermask mat...